<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .f{
            width: 310px;
            height: 190px;
            background-image: url(../HTML/picture/adv.jpg);
            position: relative;
            margin: 260px auto;
            /* margin-top:-100px;
            margin-left:-100px; */
        }

        .s1{
            width: 50px;
            height: 50px;
            background-image: url(../HTML/picture/br.gif);
            position: absolute;
            left : 0;
            top: 0;

          
        }

        .s2{
            width:50px;
            height:50px;
            background-image: url(../HTML/picture/bl.gif);
            position: absolute;
            right :0;
            bottom :0;
        }

    
    </style>
</head>
<body>
    <div class="f">
        <div class="s1"></div>
        <div class="s2"></div>

    </div>
</body>
</html>